Osteoarthritis (OA) represents the most common musculoskeletal disorder. Approximately 40 million Americans are currently affected; a number predicted to increase to 60 million within the next twenty years as a result of aging population and an increase in life expectancy, making it the fourth leading cause of disability. OA is characterized by a slow degenerative breakdown of a joint including both articular cartilage (containing the cells and matrix which produce lubrication and cushioning for the joint) and subchondral bone underlying the articular cartilage. OA can be considered a consequence of various etiologic factors. For example, it can be caused by abnormal biomechanical stress or genetic or acquired abnormalities of articular cartilage or bone. Current OA therapies include pain relief with oral NSAIDs or selective cyclooxygenase 2 (COX-2) inhibitors, intra-articular (IA) injection with agents such as corticosteroids and hyaluronan, and surgical approaches.
Joint damage, e.g., acute joint injury, such as a meniscal or ligament tear, or an intra-articular fracture can also lead to arthritis, e.g., posttraumatic arthritis. Because articular cartilage has a limited ability to repair, even small undetectable damage can often get worse over time and lead to OA. Current treatments for joint injury can include surgery and other invasive procedures focused on regeneration of damaged joints as well as treatment with agents to reduce pain and inflammation.
Mesenchymal stem cells (MSCs) are present in adult articular cartilage and upon isolation can be programmed in vitro to undergo differentiation to chondrocytes and other mesenchymal cell lineages, and may be used for cartilage regeneration. In part, the process is regulated by growth factors (TGFβs, BMPs), serum conditions and cell-cell contact. WO2011/008773 describes peptide compositions and use of those compositions for treating or preventing arthritis and joint injury and for inducing differentiation of mesenchymal cells into chondrocytes. Additionally, WO2012/129562 describes small molecule compounds, compositions and use of those compositions for amelioration of arthritis and joint injury and for inducing differentiation of mesenchymal cells into chondrocytes.
Though surgical techniques, and regenerative technology have made some progress in restoration of cartilage, slowing degeneration, and improved repair of joint damage, a continued need exists for improvement of compositions and methods for effective cartilage regeneration, treatment of joint damage and amelioration or prevention of OA.